Patching “fixed channel mon0: -1″ in aircrack-ng suite

If you’ve recently updated your kernel to 2.6.35 you may have encountered an error while using airodump-ng where the displayed channel would not match the channel you set in airmon-ng when starting your monitor device.
Before you start patching anything make sure you have tried the following:

stop networt-manager; stop avahi-daemon; killall wpa_supplicant

and then

airmon-ng start wlan0 x

where x is the channel you wish to monitor.

If after these steps you still get

fixed channel mon0: -1

in the upper right corner of your airodump-ng output, you may proceed to patching compat-wireless.

Step 1:

Get the latest compat-wireless source tarball here, or wget it with

"wget http://wireless.kernel.org/download/compat-wireless-2.6/
compat-wireless-2.6.tar.bz2"

Untar it to the current directory with

tar jxvf compat-wireless-2.6.tar.bz2

Now enter the directory with

cd compat-wireless-<tab>

Step 2:

You will now need the patch to make things work again. You can either get it here, or wget it using

wget http://patches.aircrack-ng.org/channel-negative-one-maxim.patch

and apply it using patch

patch -Np1 -i channel-negative-one-maxim.patch

You should get the following output:

patching file net/wireless/chan.c
Hunk #1 succeeded at 50 (offset 1 line).
Hunk #2 succeeded at 80 (offset 1 line).

Step 3:

You now need to compile the patched compat-wireless source with:

make

and as soon as it’s finished compiling you’ll need to execute the following as root

make install

or if you like sudo it would be

sudo make install

followed by

sudo make unload

and a reboot.

Note:
afaik make install will not overwrite your old drivers, so if you need to revert to your old config run

cd compat-wireless-<tab>
sudo make uninstall

to remove all newly installed drivers.